Principles of Operating Systems : End Semester Examination ( 3rd Sem )

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 Principles of Operating Systems

End Semester Examination, 2021-22
B. Tech - Semester : 03
Time : 03 hrs. - Max. Marks : 100

Instructions:

1. All questions are Compulsory
2. Assume missing data suitably, if any.

Section : A ( 10 x 4 = 40 Marks )

All questions are compulsory

1. Define the essential properties of the time-sharing operating system.
2. Distinguish between client-server and peer-to-peer models of distributed operating systems.
3. Enumerate any five system calls used i process management or file management.
4. Give the principles, which should be followed by any solution designed to achieve mutual exclusion in critical section problem.
5. Differentiate between preemptive and non-preemptive scheduling.
6. Define deadlock. Explain necessary condition for deadlock to occur.
7. Differentiate between logical address space and physical address space.
8. List out the major attribute and operation of file.
9. Write about Dynamic loading and linking.
10. Explain Demand paging and Memory Management Unit.

Section : B ( 3 x 6 = 18 Marks )

All questions are compulsory

1. Consider the following page reference string : 8 1 2 2 0 2 0 3 2 3 1 3 2 1 2 0 1 7 0 1. How many page fault would occur for the Optimal replacement algorithm, assuming three and four frames.
   
   OR
   Explain the Resource-Allocation-Graph. Demonstrate Resource-Allocation-Graph with a cycle but no deadlock.
2. Discuss about the evolution of virtual machine. Explain how virtualization can be implemented in operating system.
   
   OR
   With a neat sketch, explain how the logical address is translated into physical address using paging mechanism.
3. Memory Hierarchy Design and its characteristics with Suitable Diagram.
   
   OR
   Given free memory partition of 250K, 350K, 600K, 200K and 700K ( in order ), how would each of the First-fit, Best-fit and Worst-fit algorithms place processes of 110K, 260K, 261K and 498K (in order) ?

Section : C ( 3 x 10 = 30 Marks )

All questions are compulsory

1. Explain the concept of segmentation with neat diagram. What is the main problem with segmentation ?
   
   OR
   Explain how paging supports virtual memory. With neat diagram explain how logical address is translated into physical address.
2. Consider the following snapshot of the system :
   
   

   Process	Max	Allocation	Available
   	A, B, C, D	A, B, C, D	A, B, C, D
   P0	6 0 0 1	5 0 0 1	2 3 1 1
   P1	2 7 5 0	1 0 0 1
   P2	2 3 5 6	1 2 5 4
   P3	1 6 5 3	0 6 3 3
   P4	1 6 5 6	0 2 1 2

   
   Using Banker's algorithm, answer the following questions:
   i) How many resources of type A, B, C, D are there?
   ii) What are the contents of need matrix ?
   iii) Find if the system is in safe state ? If it is, find the safe sequence.
   
   OR
   What are directories? List different types of directory structure with examples. Mention their advantages and disadvantages.
3. What's difference between CPU cache and TLB and also RAM and ROM ?
   
   OR
   What is swapping and benefits of swapping and explain also input output interface, modes of data transfer ?

Section : D ( 1 x 12 = 12 Marks )

All questions are compulsory

1. Discuss the concept of Disk scheduling in Operating system? The requested tracks, in the order received are : 65, 48, 49, 58, 80, 120, 160, 258, 174. Apply the following disk scheduling algorithms. Starting tracks at 100.
   i) FCFS ii) C- SCAN iii) LOOK
   
   OR
   Direct memory access is used for high-speed I/O devices in order to avoid increasing the CPU's execution load. How does the CPU interface with the device to coordinate the transfer.
   

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